High speed quenching oil composition



United States Patent Office 3,205,100 Patented Sept. 7, 1965 3,205,100 HIGH SPEED QUENCHING OIL COMPOSITION Frederick E. Tice, Bayonne, and George B. Morgan,

Avenel, Nl, assignors to Esso Research and Engineering Company, a corporation of Delaware No Drawing. Filed Nov. 22, 1961, Ser. No. 154,344 5 Claims. (Cl. 148-29) This invention relates to oil compositions which are suitable for use as quenching oils, and to their preparation and use. More specifically, this invention concerns quenching oil compositions which contain oxidized asphaltic materials and which exhibit high quenching speeds.

The method of hardening ferrous metals by heating them to a temperature of approximately 1650 F. and then rapidly cooling them in order to increase their hardened structure is well known. By using this method of metallic hardening, it is possible to upgrade carbon steels so that they are capable of withstanding severe service conditions which would otherwise require the use of expensive metal alloys. The cooling step in this procedure is termed quenching. It is also known that an increase in the speed of quenching results in increased metallic hardness.

There are many materials which have been utilized from time to time as quenching media. Examples of such materials include wool grease, brine, linseed oil, whale oil, cottonseed oil, and mineral oil. Water, for example, has been used and exhibits an exceptional quenching speed but it also promotes metallic brittleness. The present trend is toward the use of mineral oils containing additives which improve the heat removal properties of the oil. Additives such as homopolymers and copolymers of olefins and diolefins, aromatic naphtha resins, cylinder stocks and the like have been used for this purpose. It has now been found, and forms the substance of this invention, that the addition of from 0.5 to 15.0, e.g. 1.0 to 8.0, wt. percent of oxidized asphalts to certain base oils, results in finished quenching oils which exhibit an exceptional quenching speed.

The oxidized asphalt additives of the present invention are those which can be prepared from any asphaltic crude oil. Examples of asphaltic crude oils are Lagunillas, Bachaquero and Tia Juana medium crude oils. Residual asphalts suitable for the preparation of oxidized asphalts for use in the present invention consist of that portion of an asphaltic crude which has been steam distilled and is withdrawn from the bottom of a vacuum distillation column. Suitable residual asphalts have a Furol viscosity at 210 F. of from 100 to 10,000, a Furol viscosity at 275 F. of 100 to 500, and a penetration at 77 F. of from 15 to 200. More preferred are those with a Furol viscosity at 275 F. of from 150 to 275 and a penetration of from 85 to 200 at 77 F. The method of determining penetration values is described in ASTMD552.

The oxidized asphalts suitable for use in the present invention are obtained by subjecting residual asphalts discussed above, to air blowing at temperatures of from 400 to 500 F. The air blowing is continued until sufficient asphaltene has been produced in the reaction mixture to result in the desired levels of softening point. Generally, the oxidized asphalt quenching oil additives of the invention are those which exhibit softening points in the range of 100 to 220 F. More preferred oxidized asphalt additives are those with softening points within the range of 100 to 160 F. The method of obtaining softening points is described in ASTMD-3626.

Preferred oils to which the asphalt additives are added to form the inventive compositions are refined petroleum oils with a viscosity of 50 to 150, e.g. to 115, SSU at F., and a flash point in the range of 320 to 395 F. More preferred, are those petroleum oils which exhibit Saybolt Universal viscosities at 100 F. within the range of 85 to SSU and have flash points in the range of 330 to 370 F. Illustrative of such base oils are petroleum oils, which can be predominantly paraflinic, naphthenic or aromatic or any combination thereof.

In general, the quenching oil compositions of the present invention will comprise about 0.5 to 15 wt. percent of the oxidized asphalt in the base oil. As a more preferred embodiment of the present invention, 1.0 to 8.0 wt. percent of the asphalt additive, based upon total quenching oil composition weight, is added to the base oil.

Other additives may, of course, be present in the finished high speed quenching oil for the purpose of improving any of the various properties of the finished oil. Such additives may include the other known quench speed improver additives discussed above, as well as additives intended to improve oil viscosity, flash point, chemical stability, and the like.

The invention is further illustrated by the following examples.

EXAMPLE I Compositions were prepared from identical portions of a base oil. Different additives in varying quantities were added to each base oil. The compositions were then evaluated with respect to speed of quenching.

Quenching speeds were determined by using a GM. magnetic quenchometer, an instrument manufactured by General Motors Corporation, Detroit, Michigan.

The quenchometer and test procedure are fully described in a brochure published by General Motors Corporation in October 1957 entitled Process Developments Magnetic Quench Test. Pertinent portions of the above brochure are quoted below so that the principle of the instrument can be understood without consulting th brochure.

This test makes use of the properties of metals which lose their magnetism when heated above a'certain temperature known as the Curie Point and retain their magnetism when cooled below this temperature.

High purity nickel with a Curie temperature of approximately 670 F. was selected as the metal for use in this test due to its nonscaling characteristic and resistance to cracking upon repeated heating and cooling. The nickel is spherical in shape with a diameter of A3" and weighs approximately 50 grams. The volume of quenching sample utilized is 200 cc.

The test is performed by first heating the nickel ball uniformly to 1625 F. folowed by quenching into the test sample located in a magnetic field. The time required as measured by an electrical timer, for the ball to be drawn to the maget after immersion is a measure of the quench speed of the sample. Thus, a direct comparison is readily obtainable for quenchants of various speeds; the faster the oil, the shorter the time required for the nickel to regain its magnetism The formulation of the various compositions prepared n all and tested and their G.M. qucnchometer speeds are given in Table 1 following.

1 Based on total composition weight. 4

2 A commercial asphalt characterized by the following properties:

Penetration at 77 F.=22 Softening point, F.=l95 Furol vis. at 350 F.=284

3 A commercial asphalt characterized by the following properties:

Penetration at 77 F.=3O Softening point, F.=l50 Furol vis. at 300 F.=308

4 A commercial asphalt characterized by the following properties:

Penetration at 77 F. =181 Softening point, F.=10l Furol vis. at 275 F.=147 5 A commercial petroleum oil characterized by the following properties:

Say. vis.@100 F.=72.9 Color (Tag. Rob.)=l6 Flash (Open Cup), F.=335 Gravity- API=306 Cloud Point- F.=34 Pour Point F.=30

Several other compositions were prepared and tested. These compositions had the same base oils as above but used different types of commercially available polymers as quenching speed improvers. The materials tried were propane deasphalting resin available from Humble Oil Company as Dala Resins, polyisooutylene polymer available from Humble Oil Company as Vistanex LMMS, butadiene-styrene copolymer available from Humble Oil Company as Buton 100, a copolymer of unsaturated hydrocarbons from naphtha distillate available from Pennsylvania Industrial Chemical Corporation as Piccopale 100 and polymethacrylate polymer available from Rohm & Haas as Acryloid 150. Tests were conducted to determine the amount of each material required to be blended in a base oil to produce the maximum increase in quench speed. The fastest time obtained was 16.0 seconds with 9 Wt. percent speed of Dala resins.

To further illustrate the advantages of the invention nineteen commercially available quenching oils were evaluated according to the above-described procedure. The average quenching speed of these was 22.3 seconds. The fastest quenching speed was 12.9 seconds and the slowest 30.2 seconds.

In summary, it has been found that:

(1) By adding about 1.0 to 8.0 wt. percent of a specific asphalt to an oil base the quenching speed of the oil is markedly increased.

(2) The speed improving effect of these asphalts is superior to many other known resinous materials, and

(3) Quench oils containing these asphalts exhibit faster quenching speeds than most commercial quench oils.

Although the invention has been described in its preferred form with a certain degree of particularity it is to be understood that changes in detail can be resorted to without departing from the spirit and scope of the invention as hereinafter claimed.

What is claimed is:

1. In a method of quenching, useful in heat treatment of ferrous metals, wherein a metal to be treated is heated to an elevated temperature and wherein said heated metal is then rapidly quenched in a quenching medium to effect desired metallurgical changes in said metal, the improvement which comprises using as said quenching medium a composition comprising:

(a) a major portion of petroleum oil comprised in part at least of aromatic hydrocarbons, said oil having a viscosity in the range of to SUS at 100 F. and a flash point in excess of 320 F., and

(b) from 1.0 to 8.0 wt. percent of an oxidized asphalt having a softening point in the range of 100 to 160 F.

2. A composition suitable for use as a quenching oil which comprises: (a) major portion of a petroleum oil having a viscosity of from 50 to SUS at 100 F. and a flash point in excess of 320 F., and (b) from 0.5 to 15 weight percent of an oxidized asphalt having a softening point within the range of 100 to 220 F.

3. A composition as defined in claim 2 wherein said oxidized asphalt has a softening point within the range of from 100 to F.

4. A composition as defined in claim 2 wherein said petroleum oil contains aromatic hydrocarbons.

5. In a method of quenching, useful in heat treatment of ferrous metals, wherein a metal to be treated is heated to an elevated temperature and wherein said heated metal is then rapidly quenched in a quenching medium to effect desire-d metallurgical changes in said metal, the improvement which comprises using as said quenching medium a composition comprising: (a) a major portion of a petroleum oil having a viscosity of from 50 to 150 SUS at 100 F. and a flash point in excess of 320 E, and (b) from 0.5 to 15 weight percent of an oxidized asphalt having a softening point within the range of 100 to 220 F.

References Cited by the Examiner UNITED STATES PATENTS 1,535,379 4/25 Rodman et a1 148-29 X 1,818,431 8/31 Rodrnan 148-29 X 2,340,726 2/44 Zur Horst et al. l4829 X 2,521,783 9/50 Farber 148-29 3,027,315 3/62 Rodman et a1 .a 14829 X OTHER REFERENCES Bullens: Steel and Its Heat Treatment, vol. II, 4th edition, John Wiley & Sons, Inc., 1939, page 174.

Abraham: Asphalt and Allied Substances, D. Van Nostrand Co., Inc., 1938, pages 56, 4l2424, 440-452.

DAVID L. RECK, Primmy Examiner.

WINSTON A. DOUGLAS, Examiner. 

1. IN A METHOD OF QUENCHING, USEFUL IN HEAT TREATMENT OF FERROUS METALS, WHEREIN A METAL TO BE TREATED IS HEATED TO AN ELEVATED TEMPERATURE AND WHEREIN SAID HEATED METAL IS THEN RAPIDLY QUENCHED IN A QUENCHING MEDIUM TO EFFECT DESIRED METALLURGICAL CHANGES IN SAID METAL, THE IMPROVEMENT WHICH COMPRISES USING AS SAID QUENCHING MEDIUM A COMPOSITION COMPRISING: (A) A MAJOR PORTION OF PETROLEUM OIL COMPRISED IN PART AT LEAST OF AROMATIC HYDROCARBONS, SAID OIL HAVING A VISCOSITY IN THE RANGE OF 70 TO 115 SUS AT 100*F. AND A FLASH POINT IN EXCESS OF 320*F., AND (B) FROM 1.0 TO 8.0 WT. PERCENT OF AN OXIDIZED ASPHALT HAVING A SOFTENING POINT IN THE RANGE OF 100 TO 160*F. 